Cell phones... in the classroom?

Most schools have students power down their cell phones when the enter school and have strict policies to take them if they are used during class. They are a distraction. They can be used to cheat on tests. They are completely useless in the classroom...or are they? Recently, a few of our staff have started using the website: http://www.polleverywhere.com/ to create formative assessment polls for their classrooms. Since most students have unlimited texting, they have found that the instant feedback they receive from using this is every bit as valid as the 4 button clicker system the school has just purchased for use--only it is a lot cheaper and they can access it anytime they want to, without reserving it ahead of time. This use is sure to draw some controversy. Ultimately, though, isn't it useful to tap a technology students readily handle in a positive way, instead of simply leaving students disconnected?